US2199595A - Turbine - Google Patents

Description

y 1940. L. D. MILLARD 2,199,595 TURBINE Filed May 11, 1939 mllard.

Patented May 7, 1940 TURBINE Loren D. Millard, Burlington, Iowa, assignor to I Murray Iron Works Company,

Iowa, a corporation of Iowa Burlington,

Application May 11,1939, Serial No. 273,087

6 Claims.

My invention relates to improvements in turbines An. important object of the invention is to improve the turbine shown in Patent 2,122,235

issued to me under date of January 28, 1938, so

that the same may be used as a multi-stage turbine.

Afurther object of the invention is to provide means whereby the diaphragm of a multi-stage l0 turbine may be used in connection with a turbine casing, split above the center line.

A further object of the invention is to provide a diaphragm formed in major and minor segments with means for inserting the major segment into a lower casing section split above the centerline and securely holding the major segment in. place.

A further object of the invention is" to provide means for securely attaching the segments together and forming a gas-tight joint between the same.

A further object of the invention is to provide means whereby the steam. pressure cannot pass the diaphragm except through the nozzles. Other objects and advantages of the invention will be apparent during the course of the followingdescription,

In the accompanying'drawing forming. a part of this application and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a transverse vertical section through a turbine embodying my invention, the parts being in the assembled condition;

Figure 2 is a vertical section taken on. line 2-2 of Figure 1, v

Figure 3 is a detail section taken on line 3-3 of Figure 1, V v

Figure 4 is a view similar to Figure 1 with the associated elements separated, and

Figure 5 is a transverse section. taken on line 5-5 of Figure 4.

Multi-stage turbines are known and aregmade to produce better emciency or to meet special operating conditions. A stage in a turbine consists of a diaphragm anda rotating wheel or rotor. The diaphragm is a stationary partition with nozzles to direct the steam flow into the buckets or vanes on the wheel or rotor. The diaphragm must be fitted into the casing so that no steam may pass it except through the nozzles.

Since the turbine shaft must pass through the center of the diaphragm, it is necessary that the diaphragm be split in such a way that the turbine 1 shaft carrying the rotor or wheel maybe installed andre'moved. Because of the common practice of splitting the turbine casing on the, horizontal center line, it has also been the common practice to split the diaphragm on the horizontal center line.

In accordance with the present invention the diaphragmis split in such a mannerthat it may be assembled within a turbine casing which is split above the center line, as shown in my Patent 2,122,235; To accomplish this the diaphragm is formed in a lower major segment extending for considerably more than 180 and an upper minor segment extending for considerably less than 180. The casing section is split well above the center line providing a lower casing section.

extending for considerably more than 180 and an upper casing sectionor cap extending for considerably less than 180, to complete the circle, The lower casing section is preferably provided with a groove for each lower major segment thereby effectinga gas tight joint between the periphery of the lower major segment and the lower casing section. I The coacting upper minor segment is preferablysecured to the upper casing sectionorcap and may be applied to the lower major segment.

In the-drawing wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral ill designates a turbine-casing as-awhole, corresponding to the casing 10 in;my-Patent 2,122,235. This casing it is split horizontally at an elevation well above the center line,.for forming a casing section My and an upper casing section l2. The lower casing section H extends throughout considerably more than 180 while the upper casing section or cap I2 extends for considerably less than 180", the lower casing section. l I and the upper casingsection. l2. constituting an entirecircle. The upper casing section or ,capl-Z is secured to the casing section II by bolts itor the like passing through flanges I32. Extending centrally through the casing in and supported in any suitable manner, such as is indicated in my Patent 2,122,235, is a rotor shaft It. This shaft carries the wheels or rotors,,and also passes throughthe diaphragms.

Each stage in the turbine comprises a wheel or rotor mounted upon the shaft M for rotation therewith. The wheel or rotor 55 is arranged near one side of a diaphragm i6, and its buckets or vane I"! are arranged to'receive the steam pressure'discharging through the annular group of nozzles or openings 3; The turbine may include any number of these stages but only one has been Ishown and described. I

The diaphragm I6 is split upon generally radial lines I9, providing a lower major diaphragm segment 20 extending for considerably more than and an upper minor diaphragm segment 2| extending for considerably less than 180. The upper segment 2| is adapted to fit within the V- shaped recess 22 of the lower segment. The lower diaphragm segment 2%! has a semi-cylindrical recess 23 for coaction with a semi-cylindrical recess 24 formed in the upper diaphragm segment 2|, these recesses being assembled to form an opening for the shaft l4. Surrounding the recesses 23 and 24 are segmental grooves 25, to

receive carbon packing 26 or the like, to prevent the leakage of steam between the diaphragm and the shaft Ii,

The diaphragm segments 20 and 2| are made' separately, as shown. The lower diaphragm seg- I ment 20 has a periphery which is circularly.

curved and extends for considerably more than 180 and is adapted for insertion within the lower casing section through the upper open portion thereof, when the upper casing section or cap I2 is removed. This assembling is efiected by holding the diaphragm segment 20 in an angular position, as indicated in dotted lines in Figure l, and in this manner inserting the same into the annular groove 21 upon the inner side of the lower casing section I subsequently to which the diaphragm segment 2!] is turned until it assumes the upright position, with the edges of its opening 22 disposed adjacent to the meeting edges of the flanges I3. The shaft l4 and wheel or rotor l5 may now be positioned within the lower casing section as illustrated in my Patent 2,122,235, the shaft entering the recess 23 and the wheel or rotor I5 being disposed upon and adjacent to the lower diaphragm segment 20.

The upper diaphragm segment 2| may be' rigidly secured to the upper casing section or cap |2 or formed integral therewith and will be in alignment with the lower diaphragm segment 20, when the upper casing section l2 is positioned in place upon the lower casing section The contacting edges of the diaphragm segments 20 and 2| are grooved, as shown at 28, Figure 3, to receive metal keys 29. These keys serve to effect a joint between the diaphragm segments which will prevent the passage of steam through the joint, and also serving to positively connect the upper diaphragm segment with the lower diaphragm segment. This keyed connection serves to strengthen the diaphragm by transmitting the force caused by the high steam pressure on one side of the diaphragm, from the upper diaphragm segment which is not so well supported, to the lower diaphragm segment which is well supported, and causes the diaphragm segments to form in effect a unitary diaphragm. The generally radial lines upon which the diaphragm is split extend to the lines upon which the casing is split.

It is to be understood that the forms of my invention herewith shown and described are to be taken as preferred examples of the same and that various changes in the shape, size and arrangement of parts, may be resorted to, without departing from the spirit of my invention or the scope of the subjoined claims.

Having thus described my invention, what I claim is:

1. In a turbine, a casing split horizontally well above the center line for providing a lower casing section extending circumferentially for considerably more than 180 and an upper casing section extending circumierentially'for considerably less than 180", a shaft arranged within the casing, a diaphragm within the casing and having nozzles, said diaphragm having an opening to receive the shaft, said diaphragm being split along generally radial lines which extend from the opening to the periphery of the diaphragm for providing a lower diaphragm segment extending circumferentially for more than 180 and an upper diaphragm segment extending circumferentially for less than 180, the lower diaphragm segment being housed within the lower casing section and the upper diaphragm segment being housed within the upper casing section, the upper diaphragm segment being separable fromthe lower diaphragm segment, and a rotor mounted upon the shaft and disposed in cooperative relation to the diaphragm.

2. In a turbine, a casing split horizontally well above the center line for providing a lower casing section extending circumferentially for considerably more than 180 and an upper casing section extending circumferentially for considerably less than 180, the two casing sections when assembled constituting the completed casing, a shaft arranged substantially centrally within the casing, a diaphragm Within the casing and having nozzles, said diaphragm having a substantially central opening to receive the shaft, said diaphragm being split along generally radial lines extending from points adjacent to the central opening to the periphery of the diaphragm for dividing'the diaphragm intoa lower diaphragm segment'extending circumferentially for considerably more than 180 and an upper diaphragm segment extending circumferentially for considerably less than 180, the two diaphragm segments when assembled forming the completed diaphragm, the upper diaphragm segment being separable from the lower diaphragm segment and providing when removed therefrom a recess to permit of the insertion of the lower diaphragm segment into the lower casing section.

3. In a turbine, a casing split horizontally well above the center line for providing a lower casing section extending circumferentially for considerably more than 180 and an upper casing section extending circumferentially for considerably less than 180, the two casing sections when assembled forming the complete casing, a shaft arranged substantially centrally within the casing, a diaphragm within the casing and havingnozzles, said diaphragm having a substantially central opening to receive the shaft, said diaphragm being split along generally radial lines extending substantially from the substantially central opening to the periphery of the diaphragm for dividing I the diaphragm into a lower diaphragm segment extending circumferentially for considerably more than 180 and an upper diaphragm segment extending circumferentially for considerably less than 180, the two diaphragm segments when assembled forming the complete diaphragm, the upper diaphragm segment when separated from the lower diaphragm segment forming a recess in the lower diaphragm segment, the lower diaphragm segment having its periphery extending circumferentially throughout substantially the same number of degrees as the lower casing section so that the generally radial edges of the lower diaphragm segment extend to the horizontal edges of the lower casing section, the upper 70 diaphragm segment extending circumferentially throughout substantially the same number of degrees as the upper casing section so that its generally radial edges extend tothe horizontal edges of the upper casing section, and a wheel 75 mounted upon the shaft and arranged near the diaphragm.

4. In a turbine, a casing including a lower casing section extending circumferentially for considerably more than 180 to an elevation well above the center line, an upper casing section extending circumferentially for considerably less than 180, the upper and lower casing sections having meeting edges, the assembled upper and lower casing sections forming the complete casing, a diaphragm within the casing and including a lower diaphragm segment for arrangement within the lower casing section and extending circumferentially for considerably more than 180, said lower diaphragm segment having generall radial edges forming a recess, said lower diaphragm segment having an opening at the inner reduced end of the recess, an upper diaphragm segment for insertion within the recess and extending circumferentially for considerably less than 180 and having generally radial edges, said upper diaphragm segment being provided at the inner ends of its generally radial edges with an opening, the two openings being assembled to produce a main opening, the upper and lower diaphragm segments when assembled forming the complete diaphragm, the generally radial edges of the upper and lower diaphragm segments when assembled extending to points adjacent to the meeting edges of the casing sections,

a shaft extending centrally through the casing and through the main opening, a wheel mounted upon the shaft and arranged near the diaphragm, and means to prevent the passage of fluid pressure through the main opening about the shaft.

5. In a turbine, a casing split horizontally well above the center line for providing a lower casing section extending circumferentially for consider ably more than 180 and an upper casing section extending circumferentially for considerably less than 180, the upper and lower casing sections having meeting edges and when assembled forming the complete casing section, the lower casing section being provided upon its inner face with a circumferentially extending groove, a shaft arranged centrally within the casing, a diaphragm for arrangement within the casing and having nozzles, said diaphragm having a central opening to receive the shaft, said diaphragm being split along generally radial lines which extend from a point adjacent to the central opening to the periphery of the diaphragm for dividing the diaphragm into a lower diaphragm segment extending circumferentially for considerably more than 180 and an upper diaphragm segment extending circumferentially for considerably less than 180,

the upper and lower diaphragm segments when assembled having generally radial meeting edges which extend to points near the meeting edges of the assembled upper and lower casing sections, the upper diaphragm segment being separable from the lower diaphragm segment for providing a segmental recess therein, the upper diaphragm segment being secured to the upper casing section and removable therewith as a unit, the lower diaphragm segment having its periphery adapted to be inserted into the circumferentially extending groove of the lower casing section, the central opening of the diaphragm having means to prevent the passage of fluid pressure throughv the opening about the shaft.

6. In a turbine, a shaft, a casing receiving the shaft near its center line and split horizontally above the center line for providing a lower casing section extending circumferentially for more than 180 and an upper casing section extending for less than 180", the lower casing section having an opening at its top, the width of the opening being less than the diameter of the lower casing section,'a diaphragm within the casing and having nozzles, said diaphragm including a lower diaphragm. section extending circumferentially for more than 180, and an upper diaphragm section extending circumferentially for less than 180, the lower diaphragm section being arranged within the lower casing section and providing a space at its top, the lower diaphragm section having an opening to receive the shaft which opening leads into said space, the upper diaphragm section extending from the upper casing section and having an inner portion projecting into said space and extending to a point adjacent to the shaft receiving opening, the upper dia-.

phragm section being insertable within the opening at the top of the lower casing section, the assembled diaphragmsections preventing substantially the passage of fluid pressure adjacent to the shaft, and a rotor mounted upon the shaft near the diaphragm and having a diameter" smaller than the width of the of the lower casing section.

LOREN D. MILLARB.

opening at the top

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